Gas turbines with can combustors are known from various applications in power plants. The combustion process in such gas turbines can lead to dynamic can-to-can coupling. Such a dynamic or thermo acoustic thermo acoustic coupling of gas turbine can combustors may lead to strong pulsations in particular to strong low frequency pulsations, which negatively affect the stability and lifetime of the combustor. This may lead to reduced lifetime or in extreme cases to a mechanical failure of the gas turbine. In order to mitigate thermo acoustic pulsations usually dampers or resonators are installed and/or staging of the fuel supply is done as described for example in the US2010/0313568. Since low frequency dampers require large volumes this solution is not favored. Fuel staging has a detrimental impact on the emission performance due to the creation of local hot spots (leading to NOx emissions) and local cold spots (leading to CO emissions).
This type of thermo acoustic pulsations are difficult to predict analytically and can only be observed rather late in the development process, since full engine tests need to be performed in order to detect unstable modes with can-to-can interaction. Even if dampers or resonators are provided these still need tuning in a late development stage and in worst case require engine specific tuning during commissioning of each individual engine.
Coupling of the different can combustors takes place through:                the turbine inlet in the area downstream of the combustors or the combustor transition the piece to the turbine and upstream of the leading edges of the turbine's first stage vanes,        the main air supply to the burners,        cooling and leakage air supply to combustor or        cross-ignition tubes arranged between cans.        